Effects of Aluminizing on the High Temperature Oxidation Behavior of High Silicon Cast Iron
In this study, the aluminizing of high silicon cast iron by hot-dipping in pure Al melt was performed and their high temperature oxidation behaviour was tested at 750 °C for virous exposure time. After high temperature oxidation tests, the microstructure analysis of all samples were investigated by means of metallographical examination, scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectrometer (EDS) and X-ray diffractometry (XRD).The results showed that the coating layers consisted of three layer, in the sequence of Al, Fe-Al and Si-rich layers from external topcoat to substrate. Nodules graphite had a blocking effect to retard the outward diffusion of Fe atoms and impeded the growth of Fe2Al5 in C-axis. Eventually, the cast iron substrate was oxidized directly by oxygen penetration via the greater cracks and pores to form Fe oxide nodules after 750 °C oxidation for 48h.
Yansheng Yin and Xin Wang
M. B. Lin and C. J. Wang, "Effects of Aluminizing on the High Temperature Oxidation Behavior of High Silicon Cast Iron", Advanced Materials Research, Vols. 79-82, pp. 2151-2154, 2009